1. Field of the Invention
The invention relates to a power sliding apparatus of a conveyance seat.
2. Description of Related Art
Heretofore, as this type of power sliding apparatus, a technology disclosed in, for example, Japanese Patent Application Publication No. 2006-290131 (JP 2006-290131 A) has already been known. In this technology, ball screws are rotatably attached to upper rails, and ball nuts to be engaged with the ball screws are attached to lower rails. When the ball screws are rotated by a rotational force of a motor, the upper rails are slid to the lower rails. In consequence, a conveyance seat is electrically slidable even by a simple constitution.
However, in the abovementioned technology of JP 2006-290131 A, gear boxes to transmit the rotational force of the motor to the ball screws are attached to the upper rails via openings formed in the upper surfaces of the upper rails. In such attaching, the upper rail is bent substantially into a V-shape at the opening by a load applied to an anchor bracket from a sitting person via a seat belt due to an occurrence of frontal collision of the vehicle. To prevent this upper rail from being bent, the opening of the upper rail is closed with a reinforcing bracket (a bracket in JP 2006-290131 A). On the other hand, the motor is fixed to, for example, the upper rail or a cushion frame via a motor fixing bracket (not shown in JP 2006-290131 A). Therefore, the two brackets of the reinforcing bracket and the motor fixing bracket are required for this opening and the vicinity of the opening, which has been required to be simplified.